Quote:
Originally Posted by rohitmodimodi
hey puys!i have a problem with this small piece of reading comprehension,please post ur answers along with explanations if possible.
The transplantation of organs from one individual to another normally involves two major problems: (1) organ rejection is likely unless the transplantation antigens (a usually protein or carbohydrate substance (as a toxin or enzyme) capable of stimulating an immune response) of both individuals are nearly identical, and (2) the introduction of any unmatched transplantation antigens induces the development by the recipient of donor-specific lymphocytes that will produce violent rejection of further transplantations from that donor. However, we have found that among many strains of rats these “normal” rules of transplantation are not obeyed by liver transplants. Not only are liver transplants never rejected, but they even induce a state of donor-specific unresponsiveness in which subsequent transplants of other organs, such as skin, from that donor are accepted permanently. Our hypothesis is that (1) many strains of rats simply cannot mount a sufficiently vigorous destructive immune-response (using lymphocytes) to outstrip the liver’s relatively great capacity to protect itself from immune-response damage and that (2) the systemic unresponsiveness observed is due to concentration of the recipient’s donor-specific lymphocytes at the site of the liver transplant.
17. The primary purpose of the passage is to treat the accepted generalizations about organ transplantation in which of the following ways?
(A) Explicate their main features
(B) Suggest an alternative to them
(C) Examine their virtues and limitations
(D) Criticize the major evidence used to support them
(E) Present findings that qualify them
18. It can be inferred from the passage that the author believes that an important difference among strains of rats is the
(A) size of their livers
(B) constitution of their skin
(C) strength of their immune-response reactions
(D) sensitivity of their antigens
(E) adaptability of their lymphocytes
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My Answers
17 B I think the author here is giving their hypothesis as can be seen from " Our hypothesis is that (1) many ...."
He starts by saying about the present theory and then goes on to state an example that does not correspond with the present theory. Finally he stats his own theory. So B is the best option.
A connot be as he is not explaining the main features.
C He is not examinig the virtues and limitations. he is just examining an alternative.
D This is the closest one i guess. But he is not criticising the evidence.
18 C
"(1) many strains of rats simply cannot mount a sufficiently vigorous destructive immune-response ..... "
Here the answer is clear